How to pass a list and string into a generic method which has generic list parameter

Question

I have the following method

  private static void WriteReport<T>(List<T> report, string reportName)
      {
         using (StreamWriter sw = new StreamWriter(@path)
         {
            for (var row = 0; row < report.Count; row++)
            {
               for (var column = 0; column < report.ElementAt(row).Count; column++)
                  sw.Write(report[row][column] + ",");
               sw.WriteLine();
            }
         }
      }

I can only pass in the above method the List<object> as parameter but I also want to pass parameter List<List<object>> in some cases. But I couldn't figure out the correct way to do so.

Edit: Cause whenever I pass List<List<object>> only then the nested for loop can be applied but if I pass list<object> then no nested loop can be applied and not sure how to structure my method to code it correctly

I wanted to know how to write a generic method to do so and also a bit curious to see if the generic method improves code maintainability and readability as well

Answer 1

You are not be able to convert T in List from T again, the solution that i see is to overload the method like this:

    public static void Main()
    {
        WriteReport(new List<List<string>>()
        {
            new List<string>()
            {
                "Some Item",
                "Onather Item"
            },
            new List<string>()
            {
                "Test Item",
                "Demo Item"
            }
        }, "Report Name");
    }

    private static void WriteReport<T>(List<T> report, string reportName)
    {
        foreach (var item in report)
        {
            Console.WriteLine(item);
        }

    }
    private static void WriteReport<T>(List<List<T>> report, string reportName)
    {
        foreach (var item in report)
        {
            WriteReport(item, reportName);
        }
    }

    private static void WriteReport<T>(List<List<List<T>>> report, string reportName)
    {
        foreach (var item in report)
        {
            WriteReport(item, reportName);
        }
    }
    private static void WriteReport<T>(List<List<List<List<T>>>> report, string reportName)
    {
        foreach (var item in report)
        {
            WriteReport(item, reportName);
        }
    }